I'm probably gonna' be shot shot for saying this here, but I think I'm gonna' stick with my dual AE210 stack (my wallet sighs in relief

).
At least subjectively on stage last night, the low end extension the AE212 has over the AE210 stack was pretty much lost in the mix, and if anything, was maybe even a slight detriment. Minor thing on that tho, the main thing I missed was the upper mids. As soon as I switched to the AE212 I noticed a loss of presence that was a negative change for me.
Don't get spun up about this tho... a few points to make... it's not like the AE212 has an overly huge bottom... it doesn't, which IMHO is a specific feature of it over a lot of 212 cabs I've played. Also, the AE212 is one of the most mid present 212 cabs I've personally played through. Read me carefully on this tho... I am specifically saying mid present... not mid-forward. The AE212 is particularly even sounding for a 212 IMHO. That's a good thing. But I just still like the AE210's better. And finally, these are all "non-EQ" thoughts, and IMHO Berg cabs are among the best at taking EQ, if that makes any sense to y'all.
I had a pretty interesting way of testing this...
I literally stacked the 210's right next to the 212, and ran the 212 off one side of a Carvin BX1500 and the 210 stack off the other side. This literally gave me an identical everything that I could easily... even between songs... switch back and forth. It was super useful in really identifying the differences.
Now let me say that again in a different way. It was good to be able to switch quickly, because longer periods of time would've made it harder to really tell the differences. That's because, again, the AE212 is a particularly good 212 in terms of mid presence, IMHO.
I played an ash/maple Sadowsky JJ5 for a sharper J sound, my alder/rosewood Alleva Coppolo LG5 for a mellower J sound, and just for kicks, my new Jerzy Drozd, which is not only very modern sounding, but pretty mid-forward (tho for a Jerzy, it's pretty fat sounding... this one is a bit different than a lot of his stuff.). Even with the Jerzy, I tended to like the AE210's better, even tho I would say the AE210's are also mid-forward. The other end of the spectrum didn't fare as well for me. I really felt the AE212 didn't pair well with the LG5 without some EQ. The Sadwosky sounded great with both, but the ash/maple J-type sound is really "home base" with me as well, so keep that in mind.
Slight derail here, but one added pertinent thought... there's just something about the AE210's voicing that makes their mid-forward nature "ok" with me. Normally, I'd describe something particularly mid-forward as nasal or boxy, which I hate, but the AE210s just don't strike me that way for some reason.
I continue to be impressed with the AE212, but I'm keeping what I have. I'll just make one qualification... if I was playing a much sparser mix, I'd probably prefer the AE212. It's added low end extension would really do well to fill space down low in a really sweet way, where I think the added focus and tighter low end of the 210's would probably leave me reaching for the EQ. Not a big deal, again, Bergs take EQ wonderfully, but given a choice, I like to work with native voicing as much as possible... that goes for cabs, heads, and also basses.
Anyway, feel free to beat up on me all ya want, or ask questions, whatever.
Bottom line is, Jim's definitely got another winner here, but I'm gonna' stay my ground for now.